我开始学习 Qt4 和 Python,遵循我在互联网上找到的一些教程。我有以下两个文件:
lcdrange.py:
from PyQt4 import QtGui, QtCore
class LCDRange(QtGui.QWidget):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
lcd = QtGui.QLCDNumber(2)
self.slider = QtGui.QSlider()
self.slider.setRange(0,99)
self.slider.setValue(0)
self.connect(self.slider, QtCore.SIGNAL('valueChanged(int)'),
lcd, QtCore.SLOT('display(int)'))
self.connect(self.slider, QtCore.SIGNAL('valueChanged(int)'),
self, QtCore.SIGNAL('valueChanged(int)'))
layout = QtGui.QVBoxLayout()
layout.addWidget(lcd)
layout.addWidget(self.slider)
self.setLayout(layout)
def value(self):
self.slider.value()
def setValue(self,value):
self.slider.setValue(value)
主要.py:
import sys
from PyQt4 import QtGui, QtCore
from lcdrange import LCDRange
class MyWidget(QtGui.QWidget):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
quit = QtGui.QPushButton('Quit')
quit.setFont(QtGui.QFont('Times', 18, QtGui.QFont.Bold))
self.connect(quit, QtCore.SIGNAL('clicked()'), QtGui.qApp, QtCore.SLOT('quit()'))
grid = QtGui.QGridLayout()
previousRange = None
for row in range(0,3):
for column in range(0,3):
lcdRange = LCDRange()
grid.addWidget(lcdRange, row, column)
if not previousRange == None:
self.connect(lcdRange, QtCore.SIGNAL('valueChanged(int)'),
previousRange, QtCore.SLOT('setValue(int)'))
previousRange = lcdRange
layout = QtGui.QVBoxLayout()
layout.addWidget(quit)
layout.addLayout(grid)
self.setLayout(layout)
app = QtGui.QApplication(sys.argv)
widget = MyWidget()
widget.show()
sys.exit(app.exec_())
当我运行它时,我收到以下错误:
Object::connect: No such slot LCDRange::setValue(int)
Object::connect: No such slot LCDRange::setValue(int)
Object::connect: No such slot LCDRange::setValue(int)
Object::connect: No such slot LCDRange::setValue(int)
Object::connect: No such slot LCDRange::setValue(int)
Object::connect: No such slot LCDRange::setValue(int)
Object::connect: No such slot LCDRange::setValue(int)
Object::connect: No such slot LCDRange::setValue(int)
我读过 PyQt 插槽只不过是我定义的方法,那么我做错了什么?
我也在用 Ruby 学习 Qt4,这是这段代码的来源,我将它从 Ruby 翻译成 Python。在 Ruby 版本中,LCDRange 类定义如下:
class LCDRange < Qt::Widget
signals 'valueChanged(int)'
slots 'setValue(int)'
def initialize(parent = nil)
...
所以我的猜测是我必须以某种方式声明自定义插槽的存在?